JP2005278025A - Luminance/color-difference signal generating device, image compressing device, and image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a luminance/color-difference signal generating device, etc., capable of attaining power-saving and miniaturization in a process for compressing a color signal obtained from a solid-state image sensor. <P>SOLUTION: This luminance/color-difference signal generating device, etc., can attain power-saving and miniaturization by a means for generating a color signal whose color attribute is different from the color attribute of a color filter relative to an optional pixel by an interpolation operation to the pixel from a color signal outputted from the solid-state image sensor to which a color filter having a prescribed color array is attached on a light receiving face composed of a plurality of pixels, a means for generating at least one signal between a luminance signal and one color-difference signal or more relative to the pixel from a plurality of the color signals related to the optional pixel, and a means for setting a pixel for generating a luminance signal and a color-difference signal as a pixel under consideration. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a luminance / color-difference signal generation device that generates and processes a luminance signal and a color-difference signal from a color signal, a luminance signal generated from the color signal, an image compression device that compresses the color-difference signal, and a luminance generated from the color signal The present invention relates to an image processing system that performs compression, expansion, and reproduction processing of signals and color difference signals, and is particularly suitable for use in products that require power saving and downsizing rather than image quality such as capsule endoscopes and mobile phones. The present invention relates to a luminance / color difference signal generation device, an image compression device, and an image processing system.

  As shown in FIG. 12, a conventional general image processing system includes a solid-state imaging device that receives light from a subject and outputs a color signal corresponding to the amount of received light. Color signals from the image sensor are transferred as image data. In order to efficiently transfer image data, the image data is usually transferred through processing of the image data compression apparatus 102. The image data compression apparatus 102 performs compression processing on input image data based on standards such as JPEG (Joint Photograhic Expert Group) and MPEG (Moving Picture Expert Group), and then transfers the compressed image data. To do.

  By the way, assuming that the solid-state imaging device is a single plate type, in the conventional imaging apparatus 101, in order to reduce deterioration of image data due to compression processing in the image data compression apparatus 102, a color signal obtained by imaging is used. By interpolation processing, the color signals are converted into color signals R (red), G (green), and B (blue) that are three times as many as the total number of color signals. By performing the conversion process, the luminance signal Y and the color difference signals U and V, which are input signals to the image data compression apparatus 102, are generated.

  Then, the image data decompression device 103 that has received the transferred compressed image data performs decompression processing based on the standard, and the image reproduction device 104 applies the obtained luminance signal Y and color difference signals U and V to the image reproduction device 104. These signals are converted into color signals R, G, and B by an inverse operation of color space conversion processing and displayed as an image.

  Hereinafter, such an imaging device 101, an image data compression device 102 that compresses image data output from the imaging device 101, and an image that decompresses compressed image data output from the image data compression device 102 The image processing system including the data decompression device 103 and the image reproduction device 104 will be described in more detail.

  As shown in FIG. 13, the pre-stage unit 201 of the imaging apparatus 101 includes a color filter 2011, a solid-state imaging element 2012, an interpolation processing unit 2013, and a luminance / color difference signal generation unit 2014. In the color filter 2011, for example, as shown in FIG. 2A, R, G, and B color filters are arranged in a Bayer array so that light from a subject enters the solid-state imaging device 2012 via the color filter 2011. Is attached to the front surface of the solid-state image sensor 2012.

  The solid-state image sensor 2012 receives light from the subject via the color filter 2011 and outputs a color signal corresponding to the amount of received light. The solid-state image sensor 2012 includes a plurality of light receiving elements corresponding to each color filter of the color filter 2011. Yes. An output from the solid-state imaging device 2012 is input to the interpolation processing unit 2013 as a color signal.

  The interpolation processing unit 2013 is a circuit that performs interpolation processing for each pixel based on the color signal output from the solid-state image sensor 2012, and generates the color signals R, G, B. The color signals R, G, B Is input to the luminance / color difference signal generation unit 2014. The luminance / color difference signal generation unit 2014 generates the luminance signal Y and the color difference signals U and V based on the color signals R, G, and B output from the interpolation processing unit 2013. The luminance signal Y and the color difference signals U and V are input to the image compression unit 202 as image data.

  As shown in FIG. 13, the image compression unit 202 includes a frequency conversion unit 2021, a quantization unit 2022, and an encoding unit 2023. The frequency conversion unit 2021 calculates a spatial frequency component for the luminance signal Y and the color difference signals U and V in a predetermined block. For example, in the JPEG standard, one block is composed of 8 horizontal signals and 8 vertical signals, that is, 8 × 8 signals in each of the luminance signal Y and the color difference signals U and V. Then, DCT (Discrete Cosine Transform), which is a kind of orthogonal transform, is performed and converted into a spatial frequency component. The spatial frequency component is input to the quantization unit 2022.

  The quantization unit 2022 performs quantization on the spatial frequency component output from the frequency conversion unit 2021, and the quantized spatial frequency component output from the quantization unit 2022 is encoded by the encoding unit 2023. Is input. The encoding unit 2023 forms code data for the quantized spatial frequency component output from the quantizing unit 2022. For example, in the JPEG standard, run-length encoding and Huffman encoding processing are performed on the quantized spatial frequency component output from the quantizing unit 2022. The code data is input to the image expansion unit 203.

  As shown in FIG. 13, the image decompression unit 203 includes a decoding unit 2031, an inverse quantization unit 2032, and an inverse frequency conversion unit 2033. The image decompression unit 203 performs decompression processing corresponding to the compression processing performed by the image compression unit 202, and outputs a luminance signal Y and color difference signals U and V. For example, in the JPEG standard, Huffman decoding, run length decoding, inverse quantization, and inverse DCT are performed. The luminance signal Y and the color difference signals U and V output from the image expansion unit 203 are input to the subsequent stage unit 204.

  As shown in FIG. 13, the rear stage unit 204 includes color signal generation means 2041. The color signal generation unit 2041 generates color signals R, G, and B based on the luminance signal Y and the color difference signals U and V output from the image expansion unit 203.

  As described above, in the conventional image processing system, the color signals R, G, and B are generated from the color signals obtained from the solid-state imaging device by the interpolation processing for each pixel, and the color signals R, G, and B are used to generate the color signals. Since the luminance signal Y and the color difference signals U and V are generated by the spatial conversion process, the processing data amount is large and a lot of processing is required. Therefore, a large amount of power is required in the processing steps until the color signal obtained from the solid-state imaging device is compressed. Further, since means for holding the color signals R, G, B, the luminance signal Y, and the color difference signals U, V is necessary, it is difficult to reduce the size.

In connection with such image signal processing, the Bayer array color signals R, G, and B output from the single-plate image sensor are separated for each color signal, and the separated color signals R, G, and B are separated. In addition, an imaging signal processing method is disclosed in which interpolation processing is performed so that image quality deterioration due to compression means is reduced, and the interpolated color signals R, G, and B are compressed (see, for example, Patent Document 1).
JP-A-4-284087

  However, even in this imaging signal processing method, since the compression processing is performed after the interpolation processing is performed, the problem that the amount of processing data increases when the compression processing is performed cannot be solved.

  Therefore, the present invention has been made in view of the above-described problems, and by performing processing from image capturing of a subject to compression processing of image data obtained by imaging with reduced power and power saving, a solid state can be obtained. An object of the present invention is to provide a luminance / color difference signal generation device, an image compression device, and an image processing system capable of reducing power consumption and downsizing in a processing process until a color signal obtained from an image sensor is compressed. It is what.

The present invention proposes the following means in order to solve the above-described problems.
According to the first aspect of the present invention, an arbitrary pixel is detected from a color signal output from a solid-state imaging device in which a color filter having a predetermined color arrangement is attached to a light receiving surface including a plurality of pixels. Interpolating means for generating a color signal having a color attribute different from the color attribute of the color filter by interpolation, and a luminance signal or one or more color difference signals related to the pixel from the plurality of color signals related to an arbitrary pixel A luminance / color difference signal generating means for generating at least one of the signals; and a setting means for setting a pixel for generating the luminance signal and the color difference signal as a target pixel. Has proposed.

  According to the present invention, with the pixel that generates the luminance signal and the color difference signal as the target pixel, the generation process of the luminance signal and the color difference signal is performed from the plurality of color signals related to the target pixel. As a result, it is possible to reduce the number of signals handled when generating and processing luminance signals and color difference signals from color signals obtained from a solid-state image sensor, so that luminance and color difference signals are generated with reduced power consumption and size. An apparatus can be realized.

  According to a second aspect of the present invention, in the luminance / color difference signal generation device according to the first aspect, the setting unit sets the target pixel as a pixel that outputs a color signal related to green as the color attribute. A luminance / color difference signal generating device characterized by the above is proposed.

  According to the present invention, processing is performed so that a luminance signal and a color difference signal are generated at the same coordinate position as the signal obtained from the coordinate position where the green color filter is attached to the front surface of the solid-state imaging device. As a result, a green signal having a relatively strong correlation with the luminance signal component compared to the signal obtained from the coordinate position to which the color filter of the other color is attached is obtained from the solid-state image sensor instead of the signal generated by the interpolation process. Therefore, it is possible to suppress the degradation of the luminance signal.

  According to a third aspect of the present invention, in the luminance / chrominance signal generation device according to the first or second aspect, the luminance / chrominance signal generation unit generates only the luminance signal and one chrominance signal. A luminance / color difference signal generating device characterized by the above is proposed.

  According to the present invention, the ratio of the luminance signal, the first color difference signal, and the second color difference signal which is different from the first color difference signal is generally 2: 1: Therefore, it is possible to suppress degradation of image quality.

  According to a fourth aspect of the present invention, in the luminance / color difference signal generation device according to the third aspect, the color filter is a Bayer array, and the luminance / color difference signal generation unit is configured such that the target pixel is located on the solid-state imaging device. When the pixel is located in an odd row, the luminance signal and the first color difference signal are generated, and when the pixel is located in an even row, a second color difference signal different from the luminance signal and the first color difference signal is generated. A luminance / color difference signal generating device characterized by the above is proposed.

  According to the present invention, the luminance signal and the first color difference signal, and the luminance signal and the first color difference signal are different every other row at the coordinate position of the solid-state imaging device to which the Bayer array color filter is attached. Generation processing of the second color difference signal is performed. As a result, luminance signals and chrominance signals are generated at regular intervals at the coordinate position of the solid-state imaging device, so when performing compression processing by the irreversible compression method using the correlation with the peripheral signals, Degradation of image quality can be suppressed.

According to a fifth aspect of the present invention, in the luminance / color difference signal generation device according to the first aspect, the luminance / color difference signal generation unit generates the luminance / color difference signal generation unit according to a color attribute of the color filter related to the target pixel. A luminance / color difference signal generating apparatus is proposed in which a luminance signal and the color difference signal are set.
According to the present invention, since the signal generated for each color type of the color filter having a predetermined color arrangement is determined, the number of luminance signals and color difference signals to be generated can be controlled.

  According to a sixth aspect of the present invention, in the luminance / color difference signal generation device according to the fifth aspect, the luminance / color difference signal generation unit generates a luminance signal when the color attribute related to the target pixel is green. Proposing a luminance / color difference signal generating device that generates a first color difference signal when red and a second color difference signal different from the first color difference signal when blue. Yes.

  According to the present invention, when the color filter attached to the front surface of the solid-state image sensor is green, processing is performed so that a luminance signal is generated at the same coordinate position as the signal obtained from the coordinate position. When the color filter attached to the front of the element is red, the first color difference signal that is relatively correlated with red is generated compared to other color signals, and the color attached to the front of the solid-state image sensor When the filter is blue, the second color difference signal generation process different from the first color difference signal having a relatively strong correlation with blue is performed as compared with the other color signals. As a result, a signal having a relatively strong correlation with the generated luminance signal and color difference signal is used instead of the signal generated by the interpolation process, but the signal obtained from the solid-state image sensor is used as it is. Since the signal can be generated, deterioration of the luminance signal and the color difference signal can be suppressed.

  The invention according to claim 7 is directed to an arbitrary pixel from a color signal output from a solid-state imaging device in which a color filter having a predetermined color arrangement is attached to a light receiving surface including a plurality of pixels. Interpolation means for generating a color signal having a color attribute different from the color attribute of the color filter by interpolation, and a luminance signal or one or more color signals related to the pixel from the plurality of color signals related to an arbitrary pixel And a pixel belonging to a specific row or a specific column on the solid-state imaging device is set as a pixel of interest for generating the luminance signal and the color difference signal. And a luminance / color difference signal generating apparatus characterized by having a setting means.

  According to the present invention, with a signal obtained from a specific row or a specific column at a coordinate position on a solid-state image sensor as a target pixel, a luminance signal and a color difference signal are generated at the same coordinate position on the target pixel and the solid-state image sensor. Do the process. As a result, the number of signals handled when generating and processing luminance signals and color difference signals from the color signals obtained from the solid-state image sensor can be reduced, so that generation of luminance and color difference signals with reduced power consumption and downsizing can be achieved. An apparatus can be realized. In addition, luminance and chrominance signals are generated vertically and horizontally with respect to the coordinate position on the solid-state image sensor, so compression processing using an irreversible compression method that uses correlation with surrounding pixels was performed. In this case, deterioration of image quality can be suppressed.

  According to an eighth aspect of the present invention, in the luminance / color difference signal generation device according to the seventh aspect, the setting means sets the row to be the specific row or the column to be the specific column according to a certain pattern. A luminance / color difference signal generating device is proposed.

  According to the present invention, since the luminance signal and the color difference signal are generated according to a certain rule, the number of signals to be handled can be controlled, and the compression processing by the irreversible compression method using the correlation with the surrounding pixels is performed. In addition, deterioration of image quality can be suppressed.

According to a ninth aspect of the present invention, in the luminance / color difference signal generation device according to the seventh aspect, the luminance / color difference signal generation means generates the luminance signal generated for each of the specific row or the specific column, and The present invention proposes a luminance / color difference signal generating apparatus in which the color difference signal is set.
According to the present invention, since the signal generated for each specific row or specific column is determined at the coordinate position of the solid-state imaging device, the number of luminance signals and color difference signals to be generated can be controlled.

  According to a tenth aspect of the present invention, in the luminance / color-difference signal generation device according to the seventh aspect, the color filter is a Bayer array, and the luminance / color-difference signal generation unit is configured to display the luminance / color difference signal generation unit when the specific row is an odd-numbered row The luminance signal and the first chrominance signal are generated, and when the row is an even number, a second chrominance signal different from the luminance signal and the first chrominance signal is generated, respectively, or when the specific column is an odd column A luminance / color difference signal generating device, wherein the luminance signal and the first color difference signal are generated, and the second color difference signal different from the luminance signal and the first color difference signal is generated in the case of an even number column. is suggesting.

  According to the present invention, the luminance signal and one color difference signal, and the luminance signal and the other of the luminance signal and the other at every other row or every other column at the coordinate position of the solid-state imaging device to which the Bayer array color filter is attached. Performs color difference signal generation processing. As a result, luminance signals and chrominance signals are generated at regular intervals at the coordinate position of the solid-state imaging device, so when performing compression processing by the irreversible compression method using the correlation with the peripheral signals, Degradation of image quality can be suppressed.

  The invention according to claim 11 is the luminance / color-difference signal generation apparatus according to claim 1 or 7, wherein the plurality of luminance / color-difference signal generation units having different processing targets and the plurality of luminance / color-difference signal generations A luminance / color difference signal generating apparatus is further proposed, which further comprises selection means for selecting a corresponding luminance / color difference signal generating means from the means.

  According to the present invention, the selection unit selects the optimum luminance / color difference signal generation unit, and the selected luminance / color difference signal generation unit generates the luminance signal and the color difference signal. As a result, it is possible to select the optimum luminance / color difference signal generation means for the luminance / color difference signal generation means having different processing targets depending on the application, so that improvement in image quality, high speed processing, power saving, and the like can be realized.

According to a twelfth aspect of the present invention, in the luminance / color-difference signal generation device according to the first or seventh aspect, the interpolation unit applies a color signal of a pixel located in the vicinity of the arbitrary pixel to the pixel. There has been proposed a luminance / color difference signal generation device characterized by calculating a color signal having a color attribute different from the color attribute of the color filter.
According to the present invention, since only the vicinity signal of the target pixel is used when performing the interpolation calculation, the required memory can be reduced.

The invention according to claim 13 is the luminance / color-difference signal generation device according to claim 1 or 7,
Frequency conversion means for calculating a spatial frequency component in units of blocks for each of the luminance signal and color difference signal output from the luminance / color difference signal generation device, and a quantization means for quantizing the spatial frequency component And an image compression unit comprising an encoding unit that encodes the quantized spatial frequency component.
According to the present invention, the luminance signal and the color difference signal generated by the luminance / color difference signal generation device can be compressed.

The invention according to claim 14 is the image compression apparatus according to claim 13, the decoding means for decoding the quantized spatial frequency component from the output from the image compression apparatus, and the decoded An image expansion unit comprising: an inverse quantization unit that inversely quantizes a spatial frequency component; and an inverse frequency conversion unit that calculates a luminance signal and a color difference signal in units of blocks based on the inversely quantized spatial frequency component. And an image processing system comprising: a format conversion means for converting the luminance signal and the color difference signal output from the image decompression unit into an output format required by an external device.
According to the present invention, the luminance signal and the color difference signal compressed by the image compression apparatus can be decompressed and converted into an output format required by the external device.

  According to a fifteenth aspect of the present invention, in the image processing system according to the fourteenth aspect, the format conversion unit includes an image signal generation unit that converts the luminance signal and the color difference signal into the color signal, and the image signal generation unit. An image processing system is provided that includes color signal generation means for interpolating color signals related to pixels other than the target pixel with respect to the color signals from the above.

  According to the present invention, a color image signal having the same size as the coordinate size of the solid-state imaging device can be obtained from the color signal obtained from the solid-state imaging device through the process of color signal conversion and interpolation processing in this order. .

  According to a sixteenth aspect of the present invention, in the image processing system according to the fourteenth aspect, the format conversion unit interpolates a luminance signal and a color difference signal related to a pixel other than the target pixel from the luminance signal and the color difference signal. Proposing an image processing system comprising: luminance / color difference signal interpolation means; and image signal generation means for converting the luminance signal and color difference signal from the luminance / color difference signal interpolation means into the color signal. .

  According to the present invention, a color image signal having the same size as the coordinate size of the solid-state imaging device can be obtained from the color signal obtained from the solid-state imaging device through the process of interpolation processing, color signal conversion, and this order.

  According to the present invention, from the imaging of a subject to the compression processing of image data obtained by imaging is performed by reducing the processing data and saving power, until the color signal obtained from the solid-state imaging device is compressed. In this processing step, power saving and size reduction can be achieved.

  Hereinafter, an image processing system according to an embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, the image processing system according to the first embodiment of the present invention includes a color filter 11, a single-plate solid-state imaging device 12, a setting unit 13, an interpolation unit 14, and a luminance / color difference signal. The pre-stage unit 1 including the generation unit 15, the frequency conversion unit 21, the quantization unit 22, the image compression unit 2 including the encoding unit 23, the decoding unit 31, the inverse quantization unit 32, and the inverse unit The image expansion unit 3 includes a frequency conversion unit 33, and the subsequent unit 4 includes an image signal generation unit 41 and a color signal generation unit 42.

  The pre-stage unit 1 receives light and generates a luminance signal Y and color difference signals U and V. As described above, the color filter 11, the solid-state imaging device 12, the setting unit 13, and the interpolation unit. 14 and luminance / color difference signal generation means 15. As the color filter 11, for example, as shown in FIG. 2A, a primary color filter in which R (red), G (green), and B (blue) color filters are arranged in a Bayer array is used. Is installed on the front surface of the solid-state image sensor 12 so that the light from the light enters the solid-state image sensor 12 through a color filter.

  The color filter 11 may be a complementary color filter as shown in FIG. The solid-state imaging device 12 receives light from the subject via the color filter 11 and outputs a color signal corresponding to the amount of received light, and includes a plurality of light receiving elements corresponding to the color filter 11. The setting unit 13 sets a pixel that generates a luminance signal and a color difference signal. The setting method will be described later.

  Based on the setting from the setting unit 13, the interpolation unit 14 interpolates the color signal output from the solid-state image sensor 12 and the color signal different from the color signal at the same coordinate position of the solid-state image sensor. Generate. The interpolation processing method will be described later. The luminance / color difference signal generation unit 15 generates a luminance signal Y and color difference signals U and V from the signal output from the interpolation unit 14. A method for generating the luminance signal Y and the color difference signals U and V will be described later. The luminance signal Y and the color difference signals U and V generated as described above are input to the image compression unit 2.

Next, processing operations of the image compression unit 2 and the image decompression unit 3 will be described.
The case where the image processing CODEC JPEG is used as the image compression unit 2 and the image decompression unit 3 will be described. The luminance signal Y and the color difference signals V and U are shown in (A), (B), and (C) of FIG. As shown, each signal is divided into blocks of horizontal 8 signals × vertical 8 signals as a unit, and compression processing by the image compression unit 2 is performed for each block.

  The image compression unit 2 generates code data for the luminance signal Y and the color difference signals U and V generated by the preceding unit 1, and as described above, the frequency conversion unit 21 and the quantization unit 22 are used. And an encoding means 23. The frequency conversion means 21 performs discrete cosine conversion and converts it into a spatial frequency component. The quantizing unit 22 quantizes the spatial frequency component output from the frequency converting unit 21.

  The encoding unit 23 performs run-length encoding and Huffman encoding on the quantized spatial frequency component output from the quantization unit 22 to generate code data. The code data generated by the image compression unit 2 as described above is recorded and stored in a memory or the like, or transmitted to the receiving side. The stored or transmitted code data is input to the image decompression unit 3.

  The image decompression unit 3 generates a luminance signal Y and color difference signals U and V for the code data compressed by the image compression unit 2, and as described above, the decoding means 31 and the inverse quantization It comprises means 32 and inverse frequency conversion means 33. The decoding unit 31 performs Huffman decoding and run length decoding to perform decoding processing. The inverse quantization unit 32 performs inverse quantization on the spatial frequency component output from the decoding unit 31.

  The inverse frequency transform means 33 performs inverse discrete cosine transform on the inversely quantized spatial frequency component output from the inverse quantization means 32 to generate a luminance signal Y and color difference signals U and V. The luminance signal Y and the color difference signals U and V generated by the image expansion unit 3 as described above are input to the subsequent stage unit 4. The post-stage unit 4 generates an image signal for the luminance signal Y and the color difference signals U and V expanded by the image expansion unit 3, and as described above, the image signal generation unit 41 and the color signal generation unit. 42.

  The image processing generation unit 41 uses the luminance signal Y and the color difference signals U and V output from the image expansion unit 3 to correspond to the processing in the setting unit 13, the interpolation unit 14, and the luminance / color difference signal generation unit 15 in the preceding stage 1. Then, an interpolation process is performed for each signal to generate an image signal. The color difference signal generation unit 42 performs color space conversion processing on the image signal output from the image processing generation unit 41 to generate color signal R, G, and B image signals. The image signal generated by the rear stage unit 4 as described above is reproduced as an image by an image reproduction device or the like. The signal processing of the rear stage unit 4 will be described later.

Next, the operations of the setting unit 13, the interpolation unit 14, and the luminance / color difference signal generation unit 15 in this embodiment will be described in detail.
In general, an equation for calculating the luminance signal Y and the color difference signals U and V from the color signals R, G, and B is expressed by [Equation 1].

FIG. 4 is a diagram schematically showing the light receiving surface of the solid-state imaging device 12, and R, G, and B in FIG. 4 each receive light that has passed through a color filter 11 that is a primary color filter in a Bayer array. A pixel is shown. Here, in order to facilitate understanding of the following explanation, the following definition is made. That is, when the coordinates of the pixel G at the upper left corner in the figure are (1, 1), the coordinates of the pixel A at the position X from the pixel G in the vertical direction and Y in the horizontal direction are set to (X, Y). , The output from the pixel A is represented by _AXY .

  In the present invention, a luminance signal Y and color difference signals U and V are generated based on the following principle for the color signal output from the solid-state image pickup device 12 including the color filter 11 having the above-described configuration, Output to the compression unit 2. That is, the setting unit 13 sets the interpolation unit 14 to generate the luminance signal Y and the color difference signals U and V of the pixel from which the green color signal is obtained in the solid-state imaging device 12.

In the interpolation means 14, the pixel G ₂₂ at the coordinate (2, 2) in FIG. 4 is set as the target pixel, and the pixel R ₂₂ at the same coordinate position as the target pixel is the coordinate (2, 1) of the same color and the peripheral pixel of the target pixel. ), (2, 3) using the pixels R ₂₁ and R ₂₃ , and the pixel B ₂₂ is a pixel B _{12 of} coordinates (1, 2), (3, 2) that is the peripheral pixel of the target pixel of the same color, _Obtained using B32.

Further, the luminance / color difference signal generation unit 15 generates a luminance signal Y ₂₂ and a color difference signal V ₂₂ by using the target pixel G ₂₂ and the pixel R ₂₂ and the pixel B ₂₂ generated by the interpolation unit 14. The equations for generating the luminance signal Y ₂₂ and the color difference signal V ₂₂ performed by the interpolation unit 14 and the luminance / color difference signal generation unit 15 use the pixels R ₂₁ , R ₂₃ , G ₂₂ , B ₁₂ , and B ₃₂ in FIG. It is expressed by Equation 2].

In the formula (2), (R ₂₁ + R ₂₃ ) / 2, G ₂₂ , (B ₁₂ + B ₃₂ ) / 2 correspond to the values of the pixels R ₂₂ , G ₂₂ , and B ₂₂ , respectively. Output. Further, the luminance signal Y ₂₂ and the color difference signal V ₂₂ are output from the luminance color difference signal generation means 15. Here, for the sake of convenience, equations representing the processing of the interpolation unit 14 and the processing of the luminance / color difference signal generation unit 15 are collectively shown as [Equation 2]. The output of the interpolation unit 14 may be temporarily held as pixels R ₂₂ , G ₂₂ , and B ₂₂ , and the luminance signal Y and the color difference signals U and V may be obtained using the held values. Hereinafter, equations representing the processing of the interpolation unit 14 and the processing of the luminance / color difference signal generation unit 15 are collectively shown.

Interpolation means 14, the pixel of interest pixel G ₃₃ coordinates (3,3), in a similar manner, the pixel R _33, coordinates (2,3), using the pixel R _23, R ₄₃ of (4,3) The pixel B ₃₃ is obtained using the pixels B ₃₂ and B ₃₄ having coordinates (3, 2) and (3, 4). Then, the luminance / color difference signal generation unit 15 generates a luminance signal Y ₃₃ and a color difference signal U ₃₃ using the target pixel G ₃₃ and the obtained pixel R ₃₃ and pixel B ₃₃ . Expressions for generating the luminance signal Y ₃₃ and the color difference signal U ₃₃ are expressed by [Equation 3] using the pixels R ₂₃ , R ₄₃ , G ₃₃ , B ₃₂ , and B ₃₄ in FIG.

In the equation (3), (R ₂₃ + R ₄₃ ) / 2, G ₃₃ , (B ₃₂ + B ₃₄ ) / 2 correspond to the values of the pixels R ₃₃ , G ₃₃ , and B ₃₃ , respectively. As described above, the luminance signal Y and the color difference signal U or V for the pixel of interest are generated using all the G pixels as the pixel of interest, so that the luminance signal Y for the color signal output from the solid-state imaging device 12 is generated. The color difference signals U and V can be generated.

  According to the above method, when the pixel G is an odd row (X is an odd number) and the pixel G is an even row (X is an even number) when the pixel G is an odd row (X is an odd number). In this case, since the luminance signal Y and the color difference signal V are generated, the number of output data is the same as the number of color signals output from the solid-state image sensor 12, and the image quality generally deteriorates when compressed with JPEG. The luminance signal Y and the color difference signals U and V, which are said to be low, are generated at a ratio of 2: 1: 1. That is, the number of data is 1/3 compared to the case where the luminance signal Y and the color difference signals U and V are generated after performing the interpolation processing for each pixel of the conventional color signal.

  As described above, by setting the target pixel as the pixel G, it is possible to use the G pixel that includes a relatively large amount of luminance information as a color signal output from the solid-state imaging device 12. In general, the luminance signal is more deeply related to the cause of image quality degradation than the color difference signal. Therefore, the pixel value of the pixel of interest is obtained by interpolation, and the luminance signal Y is generated from the value. The accuracy of the generated luminance signal Y is higher when the luminance signal Y is generated using the output color signal. Therefore, it is possible to suppress deterioration in image quality due to the reduction in the number of data.

In addition, due to the characteristics of the Bayer array, R and B pixels at the same coordinate position as the target pixel can be obtained by a relatively simple calculation. As shown in FIG. 5, a circuit including only the adder 5 and the 1-bit shifter 6 It can be realized with a configuration. For example, when calculating the value of the pixel R ₂₂ , R ₂₁ is input to INDATA 1, R ₂₃ is input to INDATA 2, and when determining the value of the pixel B ₂₂ , B ₁₂ is input to INDATA 1 and B ₃₂ is input to INDATA 2.

  In the above description, R and B pixels at the same coordinate position as the target pixel G are generated using two nearest-neighboring pixels of the same color. However, not only two pixels but also peripheral pixels are weighted by position information. You may make it generate by doing. In the above description, the G pixel is the pixel of interest, and the luminance signal Y and the color difference signals U and V are generated as in [Equation 2] and [Equation 3]. In order to control the number of data, The elements to be generated may be arbitrarily determined, such as generating the luminance signal Y and the color difference signals U and V for all the target pixels G, or generating only the luminance signal Y.

For example, the pixel G ₂₂ at the coordinate (2, 2) in FIG. 4 is the target pixel, and the formula for generating the luminance signal Y ₂₂ and the color difference signals U ₂₂ and V ₂₂ at the same coordinate position as the target pixel is the pixel in FIG. Using R ₂₁ , R ₂₃ , G ₂₂ , B ₁₂ , B ₃₂ , it is expressed by [Equation 4].

  Further, in the above method, the one that generates the luminance signal Y and the color difference signals U and V at the same coordinate position as the target pixel by using all the G pixels in the color signal output from the solid-state imaging device 12 as the target pixel is shown. It was. On the other hand, the color of the color signal output from the solid-state image sensor 12 can be arbitrarily set as the pixel of interest with respect to the color signal output from the solid-state imaging device 12 such as the R and B pixels or only the R pixel. You may set it.

  For example, when the pixel of interest is an R and B pixel, the expression for generating the luminance signal Y and the color difference signals U and V at the coordinate positions (2, 3) and (3, 2) in FIG. 5] and [Expression 6].

In [Equation 5], R ₂₃ , (G ₁₃ + G ₂₂ + G ₂₄ + G ₃₃ ) / 4, and (B ₁₂ + B ₁₄ + B ₃₂ + B ₃₄ ) / 4 are the values of the pixels R ₂₃ , G ₂₃ , and B ₂₃ , respectively. Correspondingly, in [Equation 6], (R ₂₁ + R ₂₃ + R ₄₁ + R ₄₃ ) / 4, (G ₂₂ + G ₃₁ + G ₃₃ + G ₄₂ ) / 4, B ₃₂ are pixels R ₃₂ , G ₃₂ , B ₃₂ , respectively. Corresponds to the value of.

  As described above, the luminance signal Y and the color difference signal U or V for the pixel of interest are generated by using all the R and B pixels as the pixel of interest, so that the luminance of the color signal output from the solid-state imaging device 12 is reduced. Signal Y and color difference signals U and V can be generated.

  According to the above method, when the target pixel is the R pixel, the luminance signal Y and the color difference signal U are generated. When the target pixel is the B pixel, the luminance signal Y and the color difference signal V are generated. As in the case of pixels, the number of output data is the same as the number of color signals output from the solid-state image sensor 12, and Y, U, and V are generated at a ratio of 2: 1: 1.

  As described above, when the pixel of interest is the pixels R and B, when the color difference signal U is generated, an R pixel having a relatively strong correlation is generated when the color difference signal V is generated. Since the processing is performed using the B pixel having a strong correlation, the color signal output from the solid-state imaging device 12 can be used as it is. Therefore, compared with the case where the pixel of interest is the pixel G, it is possible to suppress deterioration in image quality for an image in which color information relatively affects the image quality compared to luminance information.

  Even when a complementary color filter is used as a color filter instead of the primary color filter, the same definition as the primary color filter is performed, and the luminance signal Y and the color difference signals U and V are displayed on the complementary color filter as shown in FIG. The pixels Cy, Mg, Ye, and G can be used.

  According to the configuration of the preceding stage, the luminance signal Y and the color difference signals U and V are generated based on the color signal output from the solid-state imaging device 12, and the luminance signal Y and the color difference signals U and V are The image compression unit 2 performs compression processing. Therefore, since interpolation processing is performed only for pixels of a specific color based on the color signal output from the solid-state imaging device, interpolation processing that generates an image signal by performing interpolation processing for each pixel as in the past. No means are needed. Accordingly, since the number of data output from the preceding stage is small, the time required for the compression process can be reduced. Thereby, power saving can be realized in the process until the color signal output from the solid-state image sensor is compressed.

Next, the processing operation of the post-stage unit 4 that performs processing corresponding to the setting unit 13, the interpolation unit 14, and the luminance / color difference signal generation unit 15 will be described in detail.
The subsequent stage unit 4 generates an image signal for the luminance signal Y and the color difference signals U and V expanded by the image expansion unit 3, and as described above, the image signal generation unit 41 and the color signal are generated. It comprises signal generating means 42.

  The image signal generation means 41 corresponds to the processing of the setting means 13, the interpolation means 14, and the luminance / color difference signal generation means 15 in the preceding stage 1 from the luminance signal Y and the color difference signals U and V output from the image expansion section 3. Then, an interpolation process is performed, and image signals as shown in FIGS. 7A, 7B, and 7C are generated. Here, in order to facilitate understanding of the following description, the same definition as that of the primary color filter shown in FIG. 4 is also applied to (A), (B), and (C) of FIG.

  The luminance signal Y and the color difference signals U and V output from the image expansion unit 3 can be used as they are as image signals. However, the number of signal data output from the image decompression unit 3 is 1/2 for the luminance signal Y and 1/1 for the color difference signals U and V with respect to (A), (B), and (C) in FIG. 4, the color signal output from the originally expected solid-state imaging device 12 becomes smaller than the resolution of the generated image signal.

Therefore, the missing data of (A), (B), and (C) in FIG. 7 are interpolated from the luminance signal Y and the color difference signals U and V output from the image expansion unit 3. For example, the luminance signals Y ₂₂ , Y ₂₃ , and the coordinates (2, 2), (2, 3), (3, 2), (3, 3) in (A), (B), and (C) of FIG. Y ₃₂ , Y ₃₃ , color difference signals U ₂₂ , U ₂₃ , U ₃₂ , U ₃₃ , and V ₂₂ , V ₂₃ , V ₃₂ , V ₃₃ are output from the image expansion unit 3 [Equation 2], [Equation 3]. ] Using the luminance signals Y ₂₂ and Y ₃₃ , color difference signals U ₃₃ and V ₂₂ generated by the above, and other luminance signals Y and color difference signals U and V output from the image decompression unit 3. Is done.

  As described above, by performing the process of interpolating the missing data from the luminance signal Y and the color difference signals U and V output from the image decompression unit 3, as shown in FIGS. 7A, 7B, and 7C. An image signal in YUV space, which is one form of such an image signal, can be generated.

The color signal generation unit 42 performs color space conversion on the image signals shown in FIGS. 7A, 7B, and 7C output from the image signal generation unit 41, so that the color signals R, G, B is generated.
The equation for calculating the color signals R, G, and B from the luminance signal Y and the color difference signals U and V is generally an inverse operation of [Equation 1] and is expressed by [Equation 8].

  [Equation 8] is executed for each pixel with respect to the luminance signal Y and the color difference signals U and V output from the image signal generation means 41 shown in FIGS. 7A, 7B, and 7C. Thus, an RGB space image signal, which is a form of the image signal, can be generated. The image signal generated as described above is reproduced as an image by an external device such as an image reproducing device.

  In the latter stage 4 of the configuration shown in FIG. 1, image signals are generated by converting the images in the YUV space shown in FIGS. 7A, 7B, and 7C to the image signals in the RGB space. The image signal in the YUV space output from the means 41 may be handled as an image signal as it is and reproduced as an image by an image reproducing apparatus or the like. In other words, the subsequent stage may output the image signal corresponding to the output format required by the external device using the output image signal. Therefore, the latter part can also be referred to as format conversion means.

  In the configuration of the rear stage unit 4, an image signal generation unit 41 generates an image signal in the YUV space, which is one form of the image signal, from the luminance signal Y and the color difference signals U and V, and the color signal generation unit 42 generates an image. The RGB space image signal, which is one form of the signal, is generated. However, as shown in FIG. 8, the arrangement of the image signal generation unit and the color signal generation unit may be interchanged to configure the subsequent stage.

  In the rear stage unit 7 configured as described above, the color signal generation unit 71 applies the color of the Bayer array to the luminance signal Y and the color difference signals U and V output from the image expansion unit 3 as shown in FIG. Signals R, G and B are generated. Next, the image signal generation unit 72 is an embodiment of the image signal by performing interpolation processing for interpolating missing data on the Bayer array color signals R, G, and B output from the color signal generation unit 71. An RGB space image signal is generated. The image signal generated as described above is reproduced as an image by an image reproduction device or the like, similarly to the image signal from the rear stage unit 4 shown in FIG.

Next, a second embodiment will be described.
FIG. 9 is a block diagram showing a schematic configuration of an image processing system according to the second embodiment of the present invention. About the structure which has the same function as a 1st Example, the same code | symbol is attached | subjected and description is abbreviate | omitted and only a different part is demonstrated. This embodiment is characterized by the processing of the setting unit 111, the interpolation unit 112, and the luminance / color difference signal generation unit 113.

  The setting unit 111 in this embodiment sets the interpolation unit 14 to generate a luminance signal or a color difference signal of pixels from which the color signals related to red, green, and blue are obtained in the solid-state imaging device 12, that is, all pixels. .

The interpolation unit 112 in this embodiment performs an interpolation process from the color signal output from the solid-state imaging device 12 based on the setting of the setting unit 111, and is shown in FIGS. 10 (A), (B), and (C). Such an image signal is generated. Here, in order to facilitate understanding of the following description, the same definition as that of the primary color filter shown in FIG. 4 is also applied to (A), (B), and (C) of FIG. For example, color signals R ₂₂ , R ₂₃ , coordinates (2, 2), (2, 3), (3, 2), (3, 3) in (A), (B), and (C) of FIG. The equations for calculating R ₃₂ , R ₃₃ , G ₂₂ , G ₂₃ , G ₃₂ , G ₃₃ , and B ₂₂ , B ₂₃ , B ₃₂ , B ₃₃ are given by using the pixels R, G, and B in FIG. [Expression 9]

  In this way, by interpolating the missing data for each color from the color signal output from the solid-state imaging device 12, it is possible to generate an RGB space image signal that is one form of the image signal.

The luminance / color difference signal generation unit 113 in this embodiment generates a luminance signal Y and color difference signals U and V from the image signal output from the interpolation unit 112 based on the following principle, and supplies the image signal to the image compression unit 2. Output. That is, the luminance signal Y ₂₂ is obtained using the pixel G ₂₂ in FIG. 10B and the pixels R ₂₂ and B ₂₂ having the same coordinates as the pixel G ₂₂ in FIGS. 10A and 10C. Subsequently, the color difference signal U ₂₃ is obtained by using the pixel R ₂₃ in FIG. 10A and the pixels G ₂₃ and B ₂₃ having the same coordinates as the pixel R ₂₃ in FIGS. 10B and 10C. Further, the color difference signal V ₃₂ is obtained using the pixel B ₃₂ in FIG. 10C and the pixels R ₃₂ and G ₃₂ having the same coordinates as the pixel B ₃₂ in FIGS. 10A and 10B. Expressions for generating the luminance signal Y ₂₂ and the color difference signals U ₂₃ and V ₃₂ are expressed by [Equation 10] using the color signals R, G, and B in FIGS. 10 (A), (B), and (C). The

  As described above, the luminance signal Y or the color difference signal U or V is generated from the color signal on the same coordinate with respect to the image signal output from the interpolation unit 112, and is output from the solid-state imaging device 12. A luminance signal Y and color difference signals U and V can be generated for the color signal.

  According to the above method, the luminance signal Y or the color difference signal is generated when the coordinates of the generated luminance signal or color difference signal are G pixels with respect to the color signal output from the solid-state imaging device 12, and when the coordinates are R pixels, the color difference signal U. However, since the color difference signal V is generated for the B pixel, the number of output data is the same as that of the color signal output from the solid-state image pickup device 12 as in the first embodiment. In particular, Y, U, and V, which are said to have little deterioration in image quality, are generated at a ratio of 2: 1: 1.

  As described above, since processing is performed using the G pixel when generating the luminance signal Y, the R pixel when generating the color difference signal U, and the B pixel when generating the color difference signal V, solid-state imaging is performed. The color signal output from the element 12 can be used as it is. As can be seen from [Equation 1], the luminance signal Y is correlated with the color signal G, the color difference signal U is correlated with the color signal R, the color difference signal V is correlated with the color signal B, and other color signals. The luminance signal Y, using the color signal output from the solid-state image sensor 12 rather than using a value calculated by interpolating a pixel having a high intensity from the surrounding same color signal output from the solid-state image sensor 12 Alternatively, the accuracy of the generated luminance signal Y and color difference signals U and V is higher when the color difference signal U or V is generated. Therefore, it is possible to suppress deterioration in image quality due to the reduction in the number of data.

  In the above description, the luminance signal Y or the color difference signal is generated when the coordinates of the generated luminance signal or color difference signal are G pixels with respect to the color signal output from the solid-state imaging device 12, and when the coordinates are R pixels, the color difference signal U. In the case of the B pixel, the color difference signal V is generated. However, in order to reduce image quality deterioration and simplify the calculation, the types of color signals of the color signals output from the solid-state image sensor 12 are as follows. The correspondence relationship between the types of generated signals may be changed.

  In the above description, the one-to-one relationship that the luminance signal Y or the color difference signal U or V is generated is established for each color signal of the color signal output from the solid-state imaging device 12. For example, the luminance signal Y and the color difference signal U are generated for each color signal of the color signal output from the solid-state image sensor 12 such as a luminance signal Y and a color difference signal U when the pixel is G with respect to the color signal output from the solid-state image sensor 12. A plurality of signal elements may be determined.

  According to the configuration of the preceding stage, the luminance signal Y and the color difference signals U and V are generated based on the color signal output from the solid-state imaging device 12, and the luminance signal Y and the color difference signals U and V are The image compression unit 2 performs compression processing. Therefore, since the number of data output from the preceding stage is small, the time required for the compression process can be reduced, and power saving can be realized in the process until the color signal output from the solid-state imaging device is compressed.

Next, a third embodiment will be described.
FIG. 11 is a block diagram showing a schematic configuration of an image processing system according to the third embodiment of the present invention. About the structure which has the same function as a 1st Example, the same code | symbol is attached | subjected and description is abbreviate | omitted and only a different part is demonstrated. The present embodiment is characterized by the processing of the selection unit 211, the setting unit 212, the setting unit 213, the interpolation unit 214, the interpolation unit 215, the luminance / color difference signal generation unit 216, and the luminance / color difference signal generation unit 217.

  The selection unit 211 according to the present exemplary embodiment is configured to interpolate the color signal output from the solid-state imaging device 12 based on the arrangement of the color filters constituting the color filter 11 depending on applications such as high image quality and power saving. 214 or the interpolation means 215 is selected. In addition, the setting unit 212 in this embodiment sets the generation of the luminance signal and the color difference signal of the pixels in the even-numbered rows on the solid-state imaging device 12 in the interpolation unit 214.

  The interpolation unit 214 and the luminance / color difference signal generation unit 216 in the present embodiment use the luminance signal Y and the color difference signal U based on the setting of the setting unit 212 from the color signal output from the selection unit 211 according to the following principle. , V are generated and output to the image compression unit 2.

  That is, the interpolation unit 214 pays attention to the even-numbered rows (X is an even number) in FIG. 4 and generates missing data of the color signals R, G, B at the coordinate position by interpolation processing, and the luminance / color-difference signal generation unit 216. Is a luminance signal Y, a color difference signal U, using the color signal output from the solid-state imaging device 12 on the same coordinates as the output from the interpolation means 214 and the color signals R, G, B generated by the interpolation processing. , V is generated.

For example, the equations for generating the luminance signals Y ₂₂ and Y ₂₃ and the color difference signals U ₂₃ and V ₂₂ at the coordinates (2, 2) and (2, 3) in FIG. 4 are the pixels R ₂₁ , R ₂₃ , and G in FIG. ₁₃ , G ₂₂ , G ₂₄ , G ₃₃ , B ₁₂ , B ₁₄ , B ₃₂ , B ₃₄ are used and expressed by [Equation 11].

In [Expression 11], (R ₂₁ + R ₂₃ ) / 2, G ₂₂ , (B ₁₂ + B ₃₂ ) / 2, R ₂₃ , (G ₁₃ + G ₂₂ + G ₂₄ + G ₃₃ ) / 4, (B ₁₂ + B ₁₄ + B ₃₂ + B ₃₄ ) / 4 correspond to the values of the pixels R ₂₂ , G ₂₂ , B ₂₂ , R ₂₃ , G ₂₃ , B ₂₃ , respectively, and are output from the interpolation unit 214. The luminance signals Y ₂₂ and Y ₂₃ and the color difference signals U ₂₃ and V ₂₂ are output from the luminance / color difference signal generation means 216.

  In this way, the missing data for each color signal is interpolated only in the even-numbered rows in FIG. 4, and the luminance signal Y and the color-difference signal U or V are generated for each pixel in the even-numbered rows. The luminance signal Y and the color difference signals U and V can be generated with respect to the color signal output from.

  According to the above method, for even rows in FIG. 4, when the luminance signal or color difference signal coordinates are G pixels with respect to the color signal output from the solid-state imaging device 12, the luminance signal Y and the color difference. Since the luminance signal Y and the color difference signal U are generated when the signal V is an R pixel, the number of output data is the same as the number of color signals output from the solid-state imaging device 12 as in the first embodiment, and When compressed with JPEG, Y, U, and V, which are generally said to have little deterioration in image quality, are generated at a ratio of 2: 1: 1.

  As described above, in the first embodiment, the luminance signal Y and the color difference signals U and V are generated obliquely with respect to the coordinates in FIG. 4, but in the present embodiment, the even lines in FIG. By generating the luminance signal Y and the color difference signals U and V, the luminance signal Y and the color difference signals U and V are generated so as to be arranged on a straight line. Therefore, it is possible to suppress deterioration in image quality when compression processing is performed using an irreversible compression method that uses correlation with surrounding pixels.

  In the above description, the luminance signal Y and the color difference signals U and V are generated by paying attention to even rows (X is an even number) in FIG. 4, but the luminance signals are focused on odd rows (X is an odd number). Y and color difference signals U and V may be generated.

  The setting unit 213 in the present embodiment sets the generation of the luminance signal and the color difference signal of the pixels in the even columns on the solid-state imaging device 12 in the interpolation unit 215. The interpolation means 215 and the luminance / color difference signal generation means 217 in this embodiment are based on the setting of the setting means 213 based on the setting of the setting means 213 from the color signal output from the selection means 211 on the basis of the following principle. , V are generated and output to the image compression unit 2.

  That is, the interpolation means 215 pays attention to the even-numbered columns (Y is an even number) in FIG. 4 and generates the missing data of the color signals R, G, B at the coordinate positions by interpolation processing. The luminance / color difference signal generation unit 217 uses the color signal output from the solid-state imaging device 12 on the same coordinates, which is the output from the interpolation unit 215, and the color signals R, G, and B generated by interpolation processing. A luminance signal Y and color difference signals U and V are generated.

For example, the equations for generating the luminance signals Y ₂₂ and Y ₃₂ and the color difference signals U ₂₂ and V ₃₂ at the coordinates (2, 2) and (3, 2) in FIG. 4 are the pixels R ₂₁ , R ₂₃ , R in FIG. ₄₁ , R ₄₃ , G ₂₂ , G ₃₁ , G ₃₃ , G ₄₂ , B ₁₂ , B ₃₂ are used and expressed by [Equation 12].

In [Expression _{12], (R 21 + R} 23) / 2, G 22, (B 12 + B 32) / 2, (R 21 + R 23 + R 41 + R 43) / 4, (G 13 + G 22 + G 24 + G 33) / 4 and B ₃₂ correspond to the values of the pixels R ₂₂ , G ₂₂ , B ₂₂ , R ₃₂ , G ₃₂ , B ₃₂ , respectively, and are output from the interpolation means 215. The luminance signals Y ₂₂ and Y ₃₂ and the color difference signals U ₂₂ and V ₃₂ are output from the luminance / color difference signal generation means 217.

  As described above, the missing data for each color signal is interpolated only in the even-numbered columns in FIG. 4 to generate the luminance signal Y and the color-difference signal U or V for each pixel in the even-numbered columns. The luminance signal Y and the color difference signals U and V similar to those of the generation unit 217 can be generated, and the deterioration of the image quality can be suppressed similarly to the luminance / color difference signal generation unit 217.

  According to the configuration of the preceding stage, the luminance signal Y and the color difference signals U and V are generated based on the color signal output from the solid-state imaging device 12, and the luminance signal Y and the color difference signals U and V are The image compression unit 2 performs compression processing. Therefore, similar to the effect obtained in the first embodiment, the interpolation processing means generates the image signal by performing the interpolation process for each pixel on all the pixels based on the color signal output from the solid-state imaging device. Do not need. Therefore, since the number of data output from the preceding stage is small, the time required for the compression process can be reduced, and power saving can be realized in the process until the color signal output from the solid-state imaging device is compressed.

  In addition, according to the configuration of the preceding stage, the selection unit 211 can arbitrarily select an interpolation unit that inputs a color signal output from the solid-state imaging device 12, and for example, for an input image, When the interpolating unit 214 is selected when the horizontal component is relatively large and the interpolating unit 215 is selected when the vertical component is large, the interpolating unit to be selected is determined according to the feature of the image. Can be prevented.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. .

1 is a block diagram of an image processing system according to a first embodiment. It is a figure which shows a primary color filter and a complementary color filter. It is the figure which illustrated the object of image compression. It is the figure which showed typically the light-receiving surface of a solid-state image sensor. It is a figure which shows the structure of the circuit which calculates the value of the focused pixel. It is a conceptual diagram at the time of using a complementary color filter. It is a figure which shows the image signal by which the interpolation process was carried out in the 1st Example. It is a figure which shows the modification of a 1st Example. It is a block diagram of the image processing system which concerns on a 2nd Example. It is a figure which shows the image signal by which the interpolation process was carried out in the 2nd Example. It is a block diagram of the image processing system which concerns on a 3rd Example. It is a block diagram of the conventional image processing system. It is a block diagram of the conventional image processing system.

Explanation of symbols

1, 201 ... front stage part, 2, 202 ... image compression part, 3, 203 ... image decompression part, 4, 7, 204 ... rear stage part, 5 ... adder, ... 1-bit shifter, 11, 2011 ... color filter, 12, 2012 ... solid-state image sensor, 13, 111, 212, 213 ... setting means, 14, 112, 214, 215 ... interpolation means, 15 113, 216, 217, 2014 ... Luminance / color difference signal generation means, 21, 2021 ... Frequency conversion means, 22, 2022 ... Quantization means, 23, 2023 ... Encoding means, 31, 2031, Decoding means, 32, 2032 ... Inverse quantization means, 33, 2033 ... Inverse frequency conversion means, 41, 72 ... Image signal generation means, 42, 71, 2041 ... Color Signal generating means, 101... Imaging Location, 102 ... image data compression apparatus, 103 ... image data decompression apparatus, 104 ... image reproducing apparatus, 211 ... selection unit, 2013 ... interpolation means

Claims (16)

From a color signal output from a solid-state imaging device in which a color filter having a predetermined color arrangement is attached to a light-receiving surface composed of a plurality of pixels, for any pixel, the color attribute of the color filter related to the pixel Interpolating means for generating color signals of different color attributes by interpolation calculation;
Luminance / color difference signal generating means for generating, from the plurality of color signals related to an arbitrary pixel, at least one of a luminance signal related to the pixel or one or more color difference signals;
Setting means for setting a pixel that generates the luminance signal and the color difference signal as a target pixel;
A luminance / color difference signal generating apparatus comprising:   2. The luminance / color difference signal generation apparatus according to claim 1, wherein the setting unit sets the pixel of interest to a pixel that outputs a color signal related to green as the color attribute.   3. The luminance / color difference signal generation apparatus according to claim 1, wherein the luminance / color difference signal generation unit generates only the luminance signal and one color difference signal.   The color filter has a Bayer array, and the luminance / color difference signal generation means sets the luminance signal and the first color difference signal to an even row when the target pixel is located in an odd row on the solid-state imaging device. 4. The luminance / color difference signal generation apparatus according to claim 3, wherein, when positioned, a second color difference signal different from the luminance signal and the first color difference signal is generated. 5.   The luminance / color difference signal generation unit is configured to set the luminance signal and the color difference signal to be generated according to a color attribute of the color filter relating to the target pixel. Luminance / color difference signal generator.   The luminance / color difference signal generating means generates a luminance signal when the color attribute relating to the target pixel is green, generates a first color difference signal when the color attribute is red, and generates the first color difference signal when the color attribute is blue. 6. The luminance / color difference signal generation apparatus according to claim 5, wherein a second color difference signal different from the signal is generated. From a color signal output from a solid-state imaging device in which a color filter having a predetermined color arrangement is attached to a light receiving surface composed of a plurality of pixels, for any pixel, the color attribute of the color filter related to the pixel Interpolating means for generating color signals of different color attributes by interpolation calculation;
A luminance / color difference signal generating means for generating, from a plurality of the color signals related to an arbitrary pixel, at least one of a luminance signal related to the pixel or one or more color signals;
Setting means for setting a pixel belonging to a specific row or a specific column on the solid-state imaging device as a target pixel for generating the luminance signal and the color difference signal;
A luminance / color difference signal generating apparatus comprising:   8. The luminance / color difference signal generation apparatus according to claim 7, wherein the setting unit sets a row to be the specific row or a column to be the specific column according to a certain pattern.   8. The luminance / color difference signal generation unit according to claim 7, wherein the luminance signal and the color difference signal to be generated are set for each of the specific row or the specific column. Signal generator.   The color filter has a Bayer arrangement, and the luminance / chrominance signal generation means outputs the luminance signal and the first color difference signal when the specific row is an odd row, and the luminance signal and the first when the specific row is an even row. A second color difference signal different from the color difference signal is generated, or when the specific column is an odd column, the luminance signal and the first color difference signal are generated, and when the specific column is an even column, the luminance signal and the first color signal are generated. The luminance / color difference signal generating apparatus according to claim 7, wherein a second color difference signal different from the color difference signal is generated. A plurality of the luminance / color difference signal generating means having different processing targets;
Selecting means for selecting a corresponding brightness / color difference signal generating means from the plurality of brightness / color difference signal generating means;
The luminance / color difference signal generating apparatus according to claim 1 or 7, further comprising:   The interpolation means calculates a color signal having a color attribute different from a color attribute of the color filter related to the pixel from a color signal of a pixel located in the vicinity of the arbitrary pixel. The luminance / color difference signal generating apparatus according to claim 7. The luminance / color difference signal generation device according to claim 1 or 7,
Frequency conversion means for calculating a spatial frequency component in units of blocks for each signal with respect to the luminance signal and color difference signal output from the luminance / color difference signal generation device;
Quantization means for quantizing the spatial frequency component;
Encoding means for encoding the quantized spatial frequency component;
An image compression unit comprising:
An image compression apparatus comprising: An image compression apparatus according to claim 13,
Decoding means for decoding the quantized spatial frequency component from the output from the image compression device;
Inverse quantization means for inversely quantizing the decoded spatial frequency component;
Inverse frequency conversion means for calculating a luminance signal and a color difference signal in units of blocks based on the inversely quantized spatial frequency components;
An image decompression unit comprising:
Format conversion means for converting the luminance signal and color difference signal output from the image decompression unit into an output format required by an external device;
An image processing system comprising: The format conversion means includes an image signal generation means for converting the luminance signal and the color difference signal into the color signal;
Color signal generating means for interpolating color signals related to pixels other than the target pixel with respect to the color signal from the image signal generating means;
15. The image processing system according to claim 14, further comprising: The format conversion means includes luminance / color difference signal interpolation means for interpolating luminance signals and color difference signals related to pixels other than the target pixel from the luminance signal and color difference signals;
Image signal generating means for converting the luminance signal and color difference signal from the luminance / color difference signal interpolation means into the color signal;
15. The image processing system according to claim 14, further comprising:

Images